What do we learn from "v'Zarach ha'Shemesh u'Va ha'Shemesh"?
Rav Sadya Gaon: The sun rises and sets 1 and does not cease to rise to the place from which it shined.
Rashi: Just like the sun rises in the morning and sets at night, and goes [under the Eretz] the entire night, it yearns to return to the place that it rose yesterday, to rise there again today.
Ibn Ezra: Even though the sun moves, rises and sets, it returns to its place like initially. Where it shines today is close to where it shines tomorrow. Due to its movement to north and south, at each place it shines twice annually, and once each at the northern and southern extremes. The same applies to the moon and the other five Kochvei Leket. The verse mentions only the sun, which is the biggest, just like "la'Shemesh Sam Ohel Bahem" (Tehilim 19:5) omits the stars.
Ri Kara: Do not say that also the sun is Hevel, for it rises in the morning in the east and sets at night in the west. Where it rose today, it will rise tomorrow.
Rid: It mentions the orbit of the sun and streams going to the sea, for these are a comparison to "Dor Holech?" (4).
R. Avigdor: What is the Chidush? Rather, before the sun of this Tzadik sets, the sun of another Tzadik already rose. The day that R. Akiva died, R. Yehudah ha'Nasi was born. They applied to him "v'Zarach ha'Shemesh?" The day that R. Yehudah ha'Nasi died, Rav Yehudah was born in Bavel (Kidushin 72b). Before Sarah died, Rivkah was born - "va'Yvi'eha Yitzchak [ha'Ohalah Sarah Imo] 2 " (Bereishis 24:67). Before Osni'el [ben Kenaz'] sun set, Eli's rose. Before Eli's set, Shmuel's rose - "v'Ner Elokim Terem Yichveh" (Shmuel I, 3:3).
Metzudas David: When the sun is about to set, it yearns to shine more; the Galgal forces it to set in its time.
Metzudas Tziyon: "U'Va" is like "Ki Va ha'Shemesh" (Bereishis 28:11).
Rashi there, from Bereishis Rabah 60:16: Rivkah was just like Sarah - when she entered, the constant miracles of Sarah's tent returned.
Why does it say "v'El Mekomo Sho'ef"?
Ibn Ezra: This is like "b'Avas Nafshah Sha'afah Ru'ach" (Yirmeyah 2:24) - as if it inhales Ru'ach amidst great desire to return to its place.
Rashbam: [At night,] it rushes to return to the place where it shined today.
Ri Kara: This is like "k'Eved Yish'af Tzel" (Iyov 7:2) - it longs for its time to rise in its place. Metzudas Tziyon - Sho'ef is looking [towards] and desiring a matter.
R. Avigdor: The sun could rise and set immediately. However, Hashem tells it when to rise, and where.
Metzudas David: When the sun is about to rise, it wants to return to where it was and not shine; the Galgal forces it to shine in its place 1 .
He explained that before it sets, it yearns to shine more! This is like 'Bal Korchacha (against your will) you are born, Bal Korchacha you live, and Bal Korchacha you die' (Avos 4:22). (PF)
